A new family of structurally conserved fungal effectors displays epistatic interactions with plant resistance proteins.

Autor: Lazar N; Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Gif-sur-Yvette, France., Mesarich CH; Laboratory of Molecular Plant Pathology, School of Agriculture and Environment, Massey University, Palmerston North, New Zealand., Petit-Houdenot Y; Université Paris-Saclay, INRAE, UR BIOGER, Thiverval-Grignon, France., Talbi N; Université Paris-Saclay, INRAE, UR BIOGER, Thiverval-Grignon, France., Li de la Sierra-Gallay I; Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Gif-sur-Yvette, France., Zélie E; Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Gif-sur-Yvette, France., Blondeau K; Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Gif-sur-Yvette, France., Gracy J; CNRS UMR 5048, INSERM U1054, Centre de Biochimie Structurale, Université Montpellier, Montpellier, France., Ollivier B; Université Paris-Saclay, INRAE, UR BIOGER, Thiverval-Grignon, France., Blaise F; Université Paris-Saclay, INRAE, UR BIOGER, Thiverval-Grignon, France., Rouxel T; Université Paris-Saclay, INRAE, UR BIOGER, Thiverval-Grignon, France., Balesdent MH; Université Paris-Saclay, INRAE, UR BIOGER, Thiverval-Grignon, France., Idnurm A; School of BioSciences, The University of Melbourne, Melbourne, Australia., van Tilbeurgh H; Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Gif-sur-Yvette, France., Fudal I; Université Paris-Saclay, INRAE, UR BIOGER, Thiverval-Grignon, France.
Jazyk: angličtina
Zdroj: PLoS pathogens [PLoS Pathog] 2022 Jul 06; Vol. 18 (7), pp. e1010664. Date of Electronic Publication: 2022 Jul 06 (Print Publication: 2022).
DOI: 10.1371/journal.ppat.1010664
Abstrakt: Recognition of a pathogen avirulence (AVR) effector protein by a cognate plant resistance (R) protein triggers a set of immune responses that render the plant resistant. Pathogens can escape this so-called Effector-Triggered Immunity (ETI) by different mechanisms including the deletion or loss-of-function mutation of the AVR gene, the incorporation of point mutations that allow recognition to be evaded while maintaining virulence function, and the acquisition of new effectors that suppress AVR recognition. The Dothideomycete Leptosphaeria maculans, causal agent of oilseed rape stem canker, is one of the few fungal pathogens where suppression of ETI by an AVR effector has been demonstrated. Indeed, AvrLm4-7 suppresses Rlm3- and Rlm9-mediated resistance triggered by AvrLm3 and AvrLm5-9, respectively. The presence of AvrLm4-7 does not impede AvrLm3 and AvrLm5-9 expression, and the three AVR proteins do not appear to physically interact. To decipher the epistatic interaction between these L. maculans AVR effectors, we determined the crystal structure of AvrLm5-9 and obtained a 3D model of AvrLm3, based on the crystal structure of Ecp11-1, a homologous AVR effector candidate from Fulvia fulva. Despite a lack of sequence similarity, AvrLm5-9 and AvrLm3 are structural analogues of AvrLm4-7 (structure previously characterized). Structure-informed sequence database searches identified a larger number of putative structural analogues among L. maculans effector candidates, including the AVR effector AvrLmS-Lep2, all produced during the early stages of oilseed rape infection, as well as among effector candidates from other phytopathogenic fungi. These structural analogues are named LARS (for Leptosphaeria AviRulence and Suppressing) effectors. Remarkably, transformants of L. maculans expressing one of these structural analogues, Ecp11-1, triggered oilseed rape immunity in several genotypes carrying Rlm3. Furthermore, this resistance could be suppressed by AvrLm4-7. These results suggest that Ecp11-1 shares a common activity with AvrLm3 within the host plant which is detected by Rlm3, or that the Ecp11-1 structure is sufficiently close to that of AvrLm3 to be recognized by Rlm3.
Competing Interests: The authors have declared that no competing interests exist.
Databáze: MEDLINE
Externí odkaz:
Nepřihlášeným uživatelům se plný text nezobrazuje